diff options
| author | Tejun Heo <tj@kernel.org> | 2009-02-09 22:17:40 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-10 00:41:58 +0100 |
| commit | d9a89a26e02ef9ed03f74a755a8b4d8f3a066622 (patch) | |
| tree | 35f3713bca4e6b815f6b9db92dc9d812ec7213ff /arch/x86/kernel/signal.c | |
| parent | f0d96110f9fd98a1a22e03b8adba69508843d910 (diff) | |
x86: add %gs accessors for x86_32
Impact: cleanup
On x86_32, %gs is handled lazily. It's not saved and restored on
kernel entry/exit but only when necessary which usually is during task
switch but there are few other places. Currently, it's done by
calling savesegment() and loadsegment() explicitly. Define
get_user_gs(), set_user_gs() and task_user_gs() and use them instead.
While at it, clean up register access macros in signal.c.
This cleans up code a bit and will help future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 41 |
1 files changed, 16 insertions, 25 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 7fc78b01981..8562387c75a 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -50,27 +50,23 @@ # define FIX_EFLAGS __FIX_EFLAGS #endif -#define COPY(x) { \ - get_user_ex(regs->x, &sc->x); \ -} +#define COPY(x) do { \ + get_user_ex(regs->x, &sc->x); \ +} while (0) -#define COPY_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp; \ -} +#define GET_SEG(seg) ({ \ + unsigned short tmp; \ + get_user_ex(tmp, &sc->seg); \ + tmp; \ +}) -#define COPY_SEG_CPL3(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp | 3; \ -} +#define COPY_SEG(seg) do { \ + regs->seg = GET_SEG(seg); \ +} while (0) -#define GET_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - loadsegment(seg, tmp); \ -} +#define COPY_SEG_CPL3(seg) do { \ + regs->seg = GET_SEG(seg) | 3; \ +} while (0) static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, @@ -86,7 +82,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, get_user_try { #ifdef CONFIG_X86_32 - GET_SEG(gs); + set_user_gs(regs, GET_SEG(gs)); COPY_SEG(fs); COPY_SEG(es); COPY_SEG(ds); @@ -138,12 +134,7 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, put_user_try { #ifdef CONFIG_X86_32 - { - unsigned int tmp; - - savesegment(gs, tmp); - put_user_ex(tmp, (unsigned int __user *)&sc->gs); - } + put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); put_user_ex(regs->es, (unsigned int __user *)&sc->es); put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); |